Oil Pump blueprinting with PICS

[blkfordsedan]

Yeah, I forgot about the housing bolts...

The cover and housing are machined, so sealing shouldn't be a major concern.
I'd say you should be fine. I can use a torque wrench to remove the cover on my old pump and see what it was torqued at for comparison.

[blkfordsedan]

Finally found some time to post some updated pics of the "blueprinted" oil pump. To start, I removed the bypass valve and began the grinding and clean-up on the oil inlet port. The casting flash was removed and entry into the suction cavity was radiused and everything blended smooth. I used my trusty Dremel tool with a selection of multiple tiny cutter bits and a diamond stone bit for the final blending and finish.



The entry of the pressure feed port was also treated to the same re-work...



The 90 degree turn at the end of the pressure feed port was worked over as well. The transition area was blended and the radius of the turn was smoothed out......however, the actual size of the passage exit port was not increased. The last thing you want is to make this exit port larger than the hole in the block that it's feeding! Basically, the same concepts apply that you would use for head porting.




The next step was to move on to the surface finish of the gears, housing and cover assembly. I grabbed a sheet of 600 grit and 1000 grit sand paper and an old pencil. I wrapped the sandpaper around the pencil and used it to polish the teeth of the gears to a smooth(er) finish. As the new pump operates, the teeth will wear in together and naturally get smooth, seating with each other. I then placed the sand paper flat on the top of our ceramic top stove and sanded the faces of the gears in a circular motion, applying even pressure and rotating the gears in my hand as I went. I did the same with the cover plate, checking the cover for flatness with a straight edge every so often. When the gears were done to satisfaction, I used very light pressure to smooth and polish the gear contact areas in the housing. The final step was a felt polishing bit in the Dremel at slow speed. The final result was a mirror-like finsh on the gears, cover and housing wear areas. As a type of indicator when doing any polishing work on engine components, I have a little trick that my Dad used to do. I press my Thumb nail against the surface and see how much of my thumb is reflected in the surface. I always try to polish to the point that I can clearly see the cuticle of my thumb and it reflects up to at least the first knucle. Right or wrong, I guess you could call it a "rule of thumb"





The next step was to measure the clearances in the pump. I took measurements before beginning, as well as after. First, the clearance between the driver and driven rotors was measured with a feeler gauge. You need to make sure you have a feeler gauge that measures down to .0015". You can only get as accurate as the feelers you use.....my set has .0015, .002, .003, .004, etc.. This clearance measured between .003" and .004", with no measurable difference in the "before" and "after" readings. The maximum service clearance is ~.008", so I'm in great shape. You want it to be as tight as possible to reduce leak-by.....HOWEVER, if it's too tight, the gears can lock up due to expansion when the pump (i.e. oil temp) heats up. As a side note, I left the pump in the direct sun for several hours on Saturday before checking clearances. It was soo hot, you could barely touch it with bare hands (est. 120F ??). After it cooled off, I re-checked clearances. I could actually tell the change in clearance with .001" feeler gauges. I checked the driven rotor to housing clearance, which measured somewhere between .003" and .004" and the same as the "before" measurements as well. Once again, max limit is ~.008", so I'm in good shape. Polishing the surfaces may have increased the clearance, but it's waaaay less than I can tell with a .001" feeler.....probably <.0005" at most.



I then measured the end play or housing to gear side clearance. I measured it by placing a straight edge across the top of the housing, and also by using the cover plate screwed down tight. The measurements were the same (which is a good thing) at around .003". The max limit is .0055", so I'm good here as well. The same principal of "close but leave some room for expansion" applies here as well.


On the subject of adjusting clearances....
There is no real easy way to change the gear-to-gear or driven gear-to-housing clearances. What many places that sell "bluprinted" pumps do is dis-assemble multiple pumps at once. They then mix-n-match gear sets and housings to achieve the optimum clearances through the inherent differences in manufacturing tolerances. If the gear-to-housing side clearance is too much, they can then machine down the housing sides to decrease the clearance. Obviously, polishing or machining the cover has no effect on the clearance. For what I'm doing, the factory clearance could stand to be a little tighter, but they are well within the max limits and I'm happy with it. :p

The bypass valve and passage was cleaned up and the valve now moves free and effortlessly. I haven't decided if I want to shim the spring slightly to bump up the max oil pressure or not. I'm not sure what the factory setting is, but I suspect it's sufficient for mild performance usage. Here's a pic of the finished parts, ready for a thorough cleaning and re-assembly. I will pack the cavity between the gear teeth with Vasaline to aid in priming the pump and also install a new lip seal as a measure of precaution...just in case I knicked the seal lip with a tool during all the grinding and such.



It should be self-explanitory from here on out...

[Movin]

This might be a good time to talk about the changes recently to oil so that
cat converters can be happier but non roller engines are not happy.

http://www.enginebuildermag.com/Item/3100/performance_oils_and_additives_got_zinc.aspx

This link takes you to an informative site that you can spend hours looking at the
tools and chemicals pros use, with up to date info just for pros.
Check it out there is something there for everyone.

[blkfordsedan]

Awesome link! We've had several threads about the lack of ZDDP in modern oil. When I begin assembly of my B6, I plan on using generous amounts of assembly lube that is high in ZDDP, as well as specific break in oil. I'm very cautious about new camshaft break-in. A friend of mine is a Brad Penn Oil dealer, so I plan on using that in my B6.

[zoom zoom]

tags added for easier searching purposes, this is some really good stuff your doing, thanks for sharing!